Is it time to retire cholesterol tests?
The next time you go in for a medical checkup, your doctor will probably make a mistake that could endanger your life, contends cardiologist Allan Sniderman of McGill University in Montreal, Canada. Most physicians order what he considers the wrong test to gauge heart disease risk: a standard cholesterol readout, which may indicate levels of low-density lipoprotein (LDL) or non-high density lipoprotein (non-HDL) cholesterol. What they should request instead, Sniderman argues, is an inexpensive assay for a blood protein known as apolipoprotein B (apoB).
ApoB indicates the number of cholesterol-laden particles circulating in the blood—a truer indicator of the threat to our arteries than absolute cholesterol levels, some researchers believe. Sniderman asserts that routine apoB tests, which he says cost as little as $20, would identify millions more patients who could benefit from cholesterol-cutting therapies and would spare many others from unnecessary treatment. "If I can diagnose [heart disease] more accurately using apoB, and if I can treat more effectively using apoB, it's worth 20 bucks," he says.
Sniderman and a cadre of other scientists have been stumping for apoB for years, but recent reanalyses of clinical data, together with genetic studies, have boosted their confidence. At last month's American Heart Association (AHA) meeting in Anaheim, California, for example, Sniderman presented a new take on the National Health and Nutrition Examination Survey (NHANES), a famous census of the U.S. population's health.
The reexamination, which compared people with different apoB levels but the same non-HDL cholesterol readings, crystallizes the importance of measuring the protein, he says. Across the United States, patients who have the highest apoB readings will suffer nearly 3 million more heart attacks, strokes, and other cardiovascular events in the next 15 years than will people with the lowest levels, Sniderman reported. As lipidologist Daniel Rader of the University of Pennsylvania Perelman School of Medicine puts it, the question of whether LDL cholesterol is the best measure of cardiovascular risk now has a clear answer: "No."
But plenty of scientists disagree.
